A microassembler typically consists of a system having a dynamic electrostatic template. A dynamic electrostatic template has a two-dimensional array of voltage electrodes controlled by software to create electric field patterns. The electric field patterns manipulate and align particles or chiplets, suspended in solution, into an assembly.
Some current systems employ cameras paired with microscope optics to provide feedback during the assembly process. This approach requires the camera to resolve a single particle over a large field of view. This typically involves complex optics and multiple cameras. These systems use a great deal of computational power to analyze the images, calibrate them to one another and locate defects in the assembly, to provide actuation information back to the control system. The control system uses this information to manipulate particles that are out of place into the correct orientation and/or location.
Other approaches study impedance data on the electrodes used to perform alignment. This approach tends to have sensitivity to the electrical properties of the particle in question and either requires the ability to detect a very subtle signal, or a separate probing signal. The probing signal may likely interfere with the field forces used to create and hold the assembly in place. In addition, this approach has difficulties in obtaining information about chips that move around the electrode array away from an anticipated alignment site.
The complexity and expense of these approaches give rise to interest in finding new and better approaches to acquiring feedback on the assembly process.